Emergency-brake.



A. A; DOTY.

- EMERGENCY BRAKE. APPLIOATION FILED AUG.6, 1913.

1,1243%, L Patented 1311.12, 19 15.

any;

ALBERT A. DO'IY, GREEN W D, INDIANA, ASSIGNOR OF ONE-HALF TO HENGE ORME, OF GREENWOOD, INDIANA.

- EMERGENCY-BRAKE.

I wood, in the county of Johnson and State of Indiana, have invented certain new and ,useful Improvements in Emergency-Brakes,

of which the following is a specification.

This invention relatesto emergency brakes for automobiles, and has as its object to provide a brake which may be readily embodied in the construction of the ordinary hand brake without material alteration thereof, and which will act efiectually and automatically to lock the rear wheels of the ,automobile against backward rotation as, for example, when the car is ascending a deep grade and the driver finds it necessary to change from high to low speed. 4 It frequently happens under these circumstances that the engine will stop and it is then necessary for the driver to apply the emergency brakes, leave the machine and crankthe engine. If the emergency brakes for any reason fail to hold the car, it is necessary for the driver to steer the car back down the grade or into an obstruction beside the road.

The invention therefore aims to provide a brake which will automatically positively lock the rear wheels against backward rotation, as soon as they start to so rotate, thereby allowing the macnine to stand still while the gearing is being shifted from high to low.

Another aim of the invention isto so eonstruct the brake that it will not in any way interfere with the ordinary-band and emergency brakes and may be readily rendered inoperative when it is desired to back or turn the car.

In the accompanying drawings: Figure l is a side elevation of the-brake embodying the present invention, the ordinary brake.

drum and easing being shown but the brake .band and the emergency brake being omitted for the sake of clearness. Fig. 2 is a vertical transverse sectional view through the brake, on the line of Fig. 1. Fig. '3 is a detail sectional view through the engaging end of one of the braking dogs illustrating the means .up the wear resulting the'said dogs with the braking flange.

' Corresponding and like parts are referred to pin .the following description and indi- Specification of Letters Patent.

Patented Jan. 12, 1915.

cated in all the views of the drawings by as the same reference characters.

In the drawings, the numeral 1 indicates the rear wheel of an automobile to which thebrake embodying the present invention 1s applied. The brake drum is indicated 50 by the numeral-2 and is of the ordinary construction, it comprising the usual side plate'3, upon which and within the drum is mounted the usual expanding emergency brake, against the inner side ofthe drum-2. The ordinary brake band (not shown) is to be mounted upon the drum in position to cooperate with the outer surface thereof.

The brake mechanismembodying the I present invention includes as one of its elements, an annular flange 4.-wh ich is formed integral with the side plate 3 of the brake: drum and projects laterally therefrom concentric to the drum 2, as clearly'shown in Figs. 1 and 2 of the drawings, and the inner side of this flange is smoothly finished so as to constitute a braking surface. The other side plate of the brake drum is indicated by the numeral 5 and is provided with diamet- 8 rically oppositely located pivot studs 6 it being understood that the drum is rotatable Wlth respect to the plate 5 and that'the said plate is held stationary. Mounted for rock- 1ng movement upon each of the studs 6 is a 8 braking dog 7 having a cam braking surface 8 which is eccentric to the axis of the stud so that the heel of the dog is located nearer face of the flange the plate '5 is formed npon its inner side with inwardly projectthe axis of the stud 6 than is the toe of the dog. A each of the dogs 7 and these springs are secured at their other ends to the plate 5, and serve to lightly hold the heels-of the dogs in frictional contact with the inner surface of the flange 4. The dogs are so disposed that when the wheel is rotatingforwardly, the flange 4 will ride lightly over the heels of the dogs, but when the wheel is turnedbackwardly, the rictional faces 8 of the dogswill bind firmly against the inner side ofthe' flange 4 and resist such movement. In order to limit the movement of the dogs upon their; pivot studs in a direction to rovided'for taking 7 rom the contact of cause the faces 8 to bind against the-surmg stop lugs 10 arranged in the path of movement of thee-contacting ends of the (not shown) designed to work 65 spring 9 issecured at one end'to 99 dogs. ,In orderthat the dogs may be moved to position out of contact with the-flange 4:,

a rocking member 11 is mounted upon the inner face of the plate 5 and is connected at. its ends by means of links 12 tothe inner ends of the dogs; 7, the dogs at their. said inner ends being provided with pivot ears '13 for the purpose stated; The rocker 11-is extends through the'pl ate =5 and fixed upon this shaft is an arm 14 to which is connected -one end of an operating rod 15 having-its other end connected to a foot or hand lever 15 I, t to Fig.

' same, to rock themember 11 andtherefy shiftthe Fr m ffitted through the contacting (not shown).' 4 a It will now be understood by reference 1 of the drawings that when itis desired to backthe machine or to .turn the the rod 15is moved forwardly so as links 12 in such a manner ,asto move the faces 8 of the dogs out of contact with the flange 4.

that the brake mechanism embodying the present invention does not in an way interfere with the use of the or brake andjnexpansible emergency brake.

In .order not mar the braking surface of the flange should the heel end of the dog come in contact with'thefiang'e. v It will be readily unfixed upon a relatively short shaft which is claimed as new is:

' scribed, a brake drum dog and having end forward and 'rearwardsidesof the dog, ,a

securing element fastened through one of the said ends-of the .shoe and into the' said' ,dog, and a second sec'ii'ring element threaded the foregoing, it will be apparent ina'ry bandthat the ends of the braking I dogs'may have firm engagement with the rocking movement the head of i d'erstood at this point that theshoes 15 may I be readily removed and replaced when found necessary and thatwhen they become worn to a-slight degree a end edges of the dogs for the purpose of slightly advancing their contacting faces. Having thus described-the invention what w thin insert of metal may p be fitted. between their inner vsides and the 1. In brake mechanlsm iof 'th'e class dehaving a braking surface, a supporting plate, a braking dog pivotally mounted 'upon'the plate'and having a cam end, ashoe having a curved body 7 portion disposed against the saidend of the 5 portions engaging the through the body portion of the 'shoenear its other end 'andinto the end of thedog'.

2. In brake mechanism 'of theclas's. de-...

scribed, a brake dru'myhaVing-Eii: braking surface, a supporting plate, spaced braking dogs pivotally mounted upon :the plate at diametrically opposite points. theron and provided at their outer ends withbraking -J surfaces for cooperation with the braking surface of the drum, an'arm'mounted for ing portions extending in opposite directions from its axis,

arm, said portions of the arm and to ends of the said dogs. 1

In testimony whereof I afiix my signa ture in presence of two witnesses.

Witnesses:

JAMES T. HARDEN, ORA L. HARDEN.

upon the plate and havv means for rocking saidand, links pivotally connected to the ALBERT DOTY. a 8.] 

